1. Life Cycle of a Star

2. Star's Life Cycle determined by its mass – larger a star’s mass, the shorter its life cycle mass is determined by the amount of matter that is available in its nebula Nebula: the giant cloud of gas and dust the hydrogen gas in the nebula is pulled together by gravity and it begins to spin gas spins faster, it heats up and becomes as a protostar ©2014 NASA

3. Star's Life Cycle temperature reaches 15,000,000 degrees Celsius nuclear fusion occurs in the cloud's core cloud begins to glow brightly contracts a little and becomes stable Becomes a main sequence star Will remain in this stage, shining for millions to billions of years

4. Problems for Astronomers typical star exists for billions of years Not be able to observe one star throughout its entire lifetime developed theories about the evolution of stars by studying stars in different stages of development. ©2016 The Astronomers

5. Light year Light year = 9,500,000,000,000 kilometers distance to the next nearest big galaxy, the Andromeda Galaxy, is 21 quintillion km. That's 21,000,000,000,000,000,000 km.galaxy, ≈ 2,500,000 light years away ©2015 http://regentsearth.com

6. Black Hole Scientists discovered the closest black hole – 1,600 light years from Earth. The black hole – Location: Constellation Sagittarius – With Normal star dubbed V4641 Sgr – form a violent system briefly flooded part of our Milky Way Galaxy with X-rays ejected subatomic particles moving at nearly the speed of light one day in September, 2000.